ABI40 Image Data Processing
IODP-MSP drilling and logging contractor: ESO
Hole: M0007B
Expedition: 310
Location:
Latitude: 17° 45.9462' S
Longitude:
149° 33.0682' W
Logging
date: October 16,
2005
Sea
floor depth (driller's): 56.16 mbrf (41.65 mbsl)
Sea
floor depth (logger's): 56.16 mbrf
Total
penetration: 47.93
mbsf
Total
core recovered:
27.02 m (56.37 % of cored section)
Oldest
sediment recovered:
Pleistocene sequence
Lithologies: Reef framework, algal crusts, and
microbialite matrix
ABI40: 24.75-31.15 mbsf
The ABI40 acquired acoustic images at millimetre scale resolution. The images show the acoustic hardness of the lithologies within the coral reef sequence with a pixel size of 1.1 mm horizontally by 4 mm vertically.
The images are displayed as an unwrapped
borehole cylinder and are provided in .BMP and .PDF format. A dipping plane in the
borehole will appear as a sinusoid on the image with the amplitude of this
sinusoid proportional to the dip of the plane. The images are oriented with
respect to north, hence the strike of dipping features can also be determined. Additional
processing on the accelerometer data of the image tools by a double integration
of the acceleration allowed, whenever needed, a detailed repositioning of the
recorded image data to its correct position with respect to the seafloor.
The ABI40 images of the borehole wall are unaffected by borehole fluid quality.
In hole M0007B, the ABI images are of good
quality throughout the logged section, although due to hostile borehole
conditions it was only possible to acquire images over a short (< 7 m)
interval.
Additional
information about the drilling and logging operations can be found in the
Operations section of the Site Chapter in IODP Proceedings of Expedition 310.
For further questions about the data, please contact:
Jennifer
Inwood
Phone:
011-44-116-252-3327
Fax:
011-44--116-252-3918
E-mail: iodp@le.ac.uk
For any
web site-related problem please contact:
E-mail: logdb@ldeo.columbia.edu